Multi-die inductors with coupled through-substrate via cores

ABSTRACT

A semiconductor device comprising first and second dies is provided. The first die includes a first through-substrate via (TSV) extending at least substantially through the first die and a first substantially helical conductor disposed around the first TSV. The second die includes a second TSV coupled to the first TSV and a second substantially helical conductor disposed around the second TSV. The first substantially helical conductor is configured to induce a change in a magnetic field in the first and second TSVs in response to a first changing current in the first substantially helical conductor, and the second substantially helical conductor is configured to have a second changing current induced therein in response to the change in the magnetic field in the second TSV.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application contains subject matter related to a U.S. PatentApplication by Kyle K. Kirby, entitled “SEMICONDUCTOR DEVICES WITHBACK-SIDE COILS FOR WIRELESS SIGNAL AND POWER COUPLING.” The relatedapplication, of which the disclosure is incorporated by referenceherein, is assigned to Micron Technology, Inc., and is identified asU.S. application Ser. No. 15/584,278, filed May 2, 2017.

This application contains subject matter related to a U.S. PatentApplication by Kyle K. Kirby, entitled “SEMICONDUCTOR DEVICES WITHTHROUGH-SUBSTRATE COILS FOR WIRELESS SIGNAL AND POWER COUPLING.” Therelated application, of which the disclosure is incorporated byreference herein, is assigned to Micron Technology, Inc., and isidentified as U.S. application Ser. No. 15/584,310, filed May 2, 2017.

This application contains subject matter related to a U.S. PatentApplication by Kyle K. Kirby, entitled “INDUCTORS WITH THROUGH-SUBSTRATEVIA CORES.” The related application, of which the disclosure isincorporated by reference herein, is assigned to Micron Technology,Inc., and is identified as U.S. application Ser. No. 15/584,294, filedMay 2, 2017.

This application contains subject matter related to a U.S. PatentApplication by Kyle K. Kirby, entitled “3D INTERCONNECT MULTI-DIEINDUCTORS WITH THROUGH-SUBSTRATE VIA CORES.” The related application, ofwhich the disclosure is incorporated by reference herein, is assigned toMicron Technology, Inc., and is identified as U.S. application Ser. No.15/584,965, filed May 2, 2017.

TECHNICAL FIELD

The present disclosure generally relates to semiconductor devices, andmore particularly relates to semiconductor devices including multi-dieinductors with through-substrate via cores, and methods of making andusing the same.

BACKGROUND

As the need for miniaturization of electronic circuits continues toincrease, the need to minimize various circuit elements, such asinductors, increases apace. Inductors are an important component in manydiscrete element circuits, such as impedance-matching circuits, linearfilters, and various power circuits. Since traditional inductors arebulky components, successful miniaturization of inductors presents achallenging engineering problem.

One approach to miniaturizing an inductor is to use standard integratedcircuit building blocks, such as resistors, capacitors, and activecircuitry, such as operational amplifiers, to design an active inductorthat simulates the electrical properties of a discrete inductor. Activeinductors can be designed to have a high inductance and a high Q factor,but inductors fabricated using these designs consume a great deal ofpower and generate noise. Another approach is to fabricate a spiral-typeinductor using conventional integrated circuit processes. Unfortunately,spiral inductors in a single level (e.g., plane) occupy a large surfacearea, such that the fabrication of a spiral inductor with highinductance can be cost- and size-prohibitive. Accordingly, there is aneed for other approaches to the miniaturization of inductive elementsin semiconductor devices.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a simplified cross-sectional view of a multi-die semiconductordevice including coupled inductors with through-substrate via coresconfigured in accordance with an embodiment of the present technology.

FIG. 2 is a simplified perspective view of a substantially helicalconductor disposed around a through-substrate via configured inaccordance with an embodiment of the present technology.

FIG. 3 is a simplified cross-sectional view of a multi-die semiconductordevice including coupled inductors with through-substrate via coresconfigured in accordance with an embodiment of the present technology.

FIG. 4 is a simplified cross-sectional view of a multi-die semiconductordevice including coupled inductors with through-substrate via coresconfigured in accordance with an embodiment of the present technology.

FIG. 5 is a simplified cross-sectional view of a multi-die semiconductordevice including coupled inductors with through-substrate via coresconfigured in accordance with an embodiment of the present technology.

FIG. 6 is a simplified cross-sectional view of a multi-die semiconductordevice including coupled inductors with through-substrate via coresconfigured in accordance with an embodiment of the present technology.

FIG. 7 is a simplified cross-sectional view of a multi-die semiconductordevice including coupled inductors with through-substrate via coresconfigured in accordance with an embodiment of the present technology.

FIG. 8 is a simplified perspective view of a substantially helicalconductor disposed around a through-substrate via configured inaccordance with an embodiment of the present technology.

FIGS. 9A through 9D are simplified cross-sectional views of a multi-diesemiconductor device including coupled inductors with through-substratevia cores at various stages of a manufacturing process in accordancewith an embodiment of the present technology.

FIGS. 9E through 9H are simplified perspective views of a multi-diesemiconductor device including coupled inductors with through-substratevia cores at various stages of a manufacturing process in accordancewith an embodiment of the present technology.

FIG. 10 is a flow chart illustrating a method of manufacturing amulti-die semiconductor device including coupled inductors withthrough-substrate via cores in accordance with an embodiment of thepresent technology.

DETAILED DESCRIPTION

In the following description, numerous specific details are discussed toprovide a thorough and enabling description for embodiments of thepresent technology. One skilled in the relevant art, however, willrecognize that the disclosure can be practiced without one or more ofthe specific details. In other instances, well-known structures oroperations often associated with semiconductor devices are not shown, orare not described in detail, to avoid obscuring other aspects of thetechnology. In general, it should be understood that various otherdevices, systems, and methods in addition to those specific embodimentsdisclosed herein may be within the scope of the present technology.

As discussed above, semiconductor devices are continually designed withever greater needs for inductors with high inductance that occupy asmall area. These needs are especially acute in multi-die devices withcoupled inductors in different dies, where the efficiency of theinductor coupling can depend in part upon the inductors having highinductance. Accordingly, several embodiments of semiconductor devices inaccordance with the present technology can provide multi-die coupledinductors having through-substrate via cores, which can provide highinductance and efficient coupling while consuming only a small area.

Several embodiments of the present technology are directed tosemiconductor devices comprising multiple dies. A first die of thedevice includes a first through-substrate via (TSV) extending at leastsubstantially through the first die and a first substantially helicalconductor disposed around the first TSV. A second die of the deviceincludes a second TSV coupled to the first TSV and a secondsubstantially helical conductor disposed around the second TSV. Thefirst substantially helical conductor can be a non-planar spiralconfigured to induce a change in a magnetic field in the first andsecond TSVs in response to a first changing current in the firstsubstantially helical conductor, and the second substantially helicalconductor can be a non-planar spiral configured to have a secondchanging current induced therein in response to the change in themagnetic field in the second TSV.

FIG. 1 is a simplified cross-sectional view of a multi-die semiconductordevice 100 including coupled inductors with TSV cores configured inaccordance with an embodiment of the present technology. The device 100includes a first die 101 and a second die 151. The first die 101 has afirst substrate 101 a and a first insulating material 101 b. The device100 further includes a first TSV 102 that extends at least substantiallythrough the first die 101 (e.g., extending from approximately the bottomof the first substrate 101 a to beyond an upper surface of the firstsubstrate 101 a—completely through the first substrate 101 a—and intothe first insulating material 101 b). The device 100 also includes afirst substantially helical conductor 103 (“conductor 103”) disposedaround the first TSV 102. In the present embodiment, the first conductor103 is shown to include three complete turns (103 a, 103 b, and 103 c)around the first TSV 102. The first conductor 103 can be operablyconnected to other circuit elements (not shown) by leads 120 a and 120b.

The turns 103 a-103 c of the first conductor 103 are electricallyinsulated from one another and from the first TSV 102. In oneembodiment, the first insulating material 101 b electrically isolatesthe first conductor 103 from the first TSV 102. In another embodiment,the first conductor 103 can have a conductive inner region covered(e.g., coated) by a dielectric or insulating outer layer. For example,an outer layer of the first conductor 103 can be an oxide layer, and aninner region of the first conductor 103 can be copper, gold, tungsten,or alloys thereof. The first TSV 102 can also include an outer layer anda magnetic material within the outer layer. The outer layer can be adielectric or insulating material (e.g., silicon oxide, silicon nitride,polyimide, etc.) that electrically isolates the magnetic material of thefirst TSV 102 from the first conductor 103. One aspect of the firstconductor 103 is that the individual turns 103 a-103 c define anon-planar spiral with respect to the longitudinal dimension “L” of thefirst TSV 102. Each subsequent turn 103 a-103 c is at a differentelevation along the longitudinal dimension L of the first TSV 102 in thenon-planar spiral of the first conductor 103.

According to one embodiment of the present technology, the firstsubstrate 101 a can be any one of a number of substrate materialssuitable for semiconductor processing methods, including silicon, glass,gallium arsenide, gallium nitride, organic laminates, and the like. Aswill be readily understood by those skilled in the art, athrough-substrate via, such as the first TSV 102, can be made by etchinga high-aspect-ratio hole into a substrate material and filling it withone or more materials in one or more deposition and/or plating steps.Accordingly, the first TSV 102 extends at least substantially throughthe first substrate 101 a, which is unlike other circuit elements thatare additively constructed on top of the first substrate 101 a. Forexample, the first substrate 101 a can be a thinned silicon wafer ofabout 100 μm thickness, and the first TSV 102 can extend completelythrough the first substrate 101 a, such that a lowermost portion of thefirst TSV 102 can be exposed for mechanical and/or electrical connectionto elements in another die.

The second die 151 has a second substrate 151 a, a second insulatingmaterial 151 b, and a second TSV 152 in the second die 151 extending outof the second substrate 151 a and into the second insulating material151 b. The device 100 further includes a second substantially helicalconductor 153 (“conductor 153”) disposed around the second TSV 152. Inthe present embodiment, the second conductor 153 is shown to includethree complete turns (153 a, 153 b, and 153 c) around the second TSV152. The second conductor 153 can be operably connected to other circuitelements (not shown) by leads 170 a and 170 b.

The three turns 153 a-153 c of the second conductor 153 are electricallyinsulated from one another and from the second TSV 152. In oneembodiment, the second insulating material 151 b electrically isolatesthe second conductor 153 from the second TSV 152. In another embodiment,the second conductor 153 can have a conductive inner region covered(e.g., coated) by a dielectric or insulating outer layer. For example,an outer layer of the second conductor 153 can be an oxide layer, and aninner region of the second conductor 153 can be copper, gold, tungsten,or alloys thereof. The second TSV 152 can also include an outer layerand a magnetic material within the outer layer. The outer layer can be adielectric or insulating material (e.g., silicon oxide, silicon nitride,polyimide, etc.) that electrically isolates the magnetic material of thesecond TSV 152 from the second conductor 153. One aspect of the secondconductor 153 is that the individual turns 153 a-153 c define anon-planar spiral with respect to the longitudinal dimension “L” of thesecond TSV 152. Each subsequent turn 153 a-153 c is at a differentelevation along the longitudinal dimension L of the second TSV 152 inthe non-planar spiral of the second conductor 153.

According to one embodiment of the present technology, the secondsubstrate 151 a can be any one of a number of substrate materialssuitable for semiconductor processing methods, including silicon, glass,gallium arsenide, gallium nitride, organic laminates, and the like. Aswill be readily understood by those skilled in the art, athrough-substrate via, such as the second TSV 152, can be made byetching a high-aspect-ratio hole into a substrate material and fillingit with one or more materials in one or more deposition and/or platingsteps. Accordingly, the second TSV 152 extends substantially into thesecond substrate 151 a, unlike other circuit elements that areadditively constructed on top of the second substrate 151 a. Forexample, the second substrate 151 a can be a silicon wafer of about 800μm thickness, and the second TSV 152 can extend from 30 to 100 μm intothe second substrate 151 a. In other embodiments, a TSV may extend evenfurther into a substrate material (e.g., 150 μm, 200 μm, etc.), or mayextend into a substrate material by as little as 10 μm.

According to one embodiment, the first conductor 103 can be configuredto induce a magnetic field in the first and second TSVs 102 and 152 inresponse to a current passing through the first conductor 103 (e.g.,provided by a voltage differential applied across the leads 120 a and120 b). By changing the current passing through the first conductor 103(e.g., by applying an alternating current, or by repeatedly switchingbetween high and low voltage states), a changing magnetic field can beinduced in the first and second TSVs 102 and 152, which in turn inducesa changing current in the second conductor 153. In this fashion, signalsand/or power can be coupled between a circuit comprising the firstconductor 103 and another comprising the second conductor 153.

In another embodiment, the second conductor 153 can be configured toinduce a magnetic field in the first and second TSVs 102 and 152 inresponse to a current passing through the second conductor 153 (e.g.,provided by a voltage differential applied across leads 170 a and 170b). By changing the current passing through the second conductor 153(e.g., by applying an alternating current, or by repeatedly switchingbetween high and low voltage states), a changing magnetic field can beinduced in the first and second TSVs 102 and 152, which in turn inducesa changing current in the first conductor 103. In this fashion, signalsand/or power can be coupled between a circuit comprising the secondconductor 153 and another comprising the first conductor 103.

In accordance with one embodiment of the present technology, the twoTSVs 102 and 152 can include a magnetic material (e.g., a material witha higher magnetic permeability than the materials of the first andsecond substrates 101 a and 151 a and/or the first and second insulatingmaterials 101 b and 151 b) to increase the magnetic field in the twoTSVs 102 and 152 when current is flowing through the first and/or secondconductors 103 and/or 153. The magnetic material can be ferromagnetic,ferrimagnetic, or a combination thereof. In one embodiment, the two TSVs102 and 152 can have the same composition, and in other embodiments, thetwo TSVs 102 and 152 can have different compositions. The two TSVs 102and 152 can include more than one material, either in a bulk material ofa single composition or in discrete regions of different materials(e.g., coaxial laminate layers). For example, the two TSVs 102 and 152can include nickel, iron, cobalt, niobium, or alloys thereof.

The two TSVs 102 and 152 can include a bulk material with desirablemagnetic properties (e.g., elevated magnetic permeability provided bynickel, iron, cobalt, niobium, or an alloy thereof), or can includemultiple discrete layers, only some of which are magnetic, in accordancewith an embodiment of the present technology. For example, following ahigh-aspect ratio etch and a deposition of insulator, each of the firstand second TSVs 102 and 152 can be provided in a single metallizationstep filling in the insulated opening with a magnetic material. Inanother embodiment, each of the first and second TSVs 102 and 152 can beformed in multiple steps to provide coaxial layers (e.g., two or moremagnetic layers separated by one or more non-magnetic layers). Forexample, multiple conformal plating operations can be performed before abottom-up fill operation to provide a TSV with a coaxial layer ofnon-magnetic material separating a core of magnetic material and anouter coaxial layer of magnetic material. In this regard, a firstconformal plating step can partially fill and narrow the etched openingwith a magnetic material (e.g., nickel, iron, cobalt, niobium, or analloy thereof), a second conformal plating step can further partiallyfill and further narrow the opening with a non-magnetic material (e.g.,polyimide or the like), and a subsequent bottom-up plating step (e.g.,following the deposition of a seed material at the bottom of thenarrowed opening) can completely fill the narrowed opening with anothermagnetic material (e.g., nickel, iron, cobalt, niobium, or an alloythereof). Such a structure with laminated coaxial layers of magnetic andnon-magnetic material can help to reduce eddy current losses in a TSVthrough which a magnetic flux is passing.

In accordance with one embodiment of the present technology, the firstand second TSVs 102 and 152 can be coupled in any one of a number ofways to improve the magnetic permeability of the path followed by amagnetic field generated by a current through one of the two conductors103 and 153. For example, in the embodiment illustrated in FIG. 1, thefirst TSV 102 is coupled to the second TSV 152 by a solder connection140. The solder connection 140 can be separated from the first TSV 102by a barrier material 141 and separated from the second TSV 152 byanother barrier material 142. The barrier materials 141 and 142 can beconfigured to prevent solder diffusion into the two TSVs 102 and 152.The solder material 140 can include a magnetic material to enhance itsmagnetic permeability. For example, the solder material 140 can includenickel, iron, cobalt, niobium, or alloys thereof. In other embodiments,TSVs in adjacent dies can be coupled using any one of a number of otherinterconnect methods (e.g., copper-to-copper bonding, pill and pad,interference fit, mechanical, etc.).

A conductive winding (e.g., the conductors 103 and 153) of an inductordisposed around a TSV magnetic core (e.g., the TSVs 102 and 152) neednot be smoothly helical in several embodiments of the presenttechnology. Although the conductors 103 and 153 are illustratedschematically and functionally in FIG. 1 as having turns that, in crosssection, appear to gradually increase in distance from a surface of arespective substrate, it will be readily understood by those skilled inthe art that fabricating a smooth helix with an axis perpendicular to asurface of a substrate presents a significant engineering challenge.Accordingly, a “substantially helical” conductor, as used herein,describes a conductor having turns that are separated along thelongitudinal dimension L of the TSV (e.g., the z-dimension perpendicularto the substrate surface), but which are not necessarily smoothlyvarying in the z-dimension (e.g., the substantially helical shape doesnot possess arcuate, curved surfaces and a constant pitch angle).Rather, an individual turn of the conductor can have a pitch of zerodegrees and the adjacent turns can be electrically coupled to each otherby steeply-angled or even vertical connectors (e.g., traces or vias)with a larger pitch, such that a “substantially helical” conductor canhave a stepped structure. Moreover, the planar shape traced out by thepath of individual turns of a substantially helical conductor need notbe elliptical or circular. For the convenience of integration withefficient semiconductor processing methodologies (e.g., masking withcost-effective reticles), individual turns of a substantially helicalconductor can trace out a polygonal path in a planar view (e.g., asquare, a hexagon, an octagon, or some other regular or irregularpolygonal shape around the first TSV 102). Accordingly, a “substantiallyhelical” conductor, as used herein, describes a non-planar spiralconductor having turns that trace out any shape in a planar view (e.g.,parallel to the plane of the substrate surface) surrounding a centralaxis, including circles, ellipses, regular polygons, irregular polygons,or some combination thereof.

FIG. 2 is a simplified perspective view of a substantially helicalconductor 204 (“conductor 204”) disposed around a through-substrate via202 configured in accordance with an embodiment of the presenttechnology. For more easily illustrating the substantially helical shapeof the conductor 204 illustrated in FIG. 2, the substrate material,insulating materials, and other details of the device in which theconductor 204 and the TSV 202 are disposed have been eliminated from theillustration. As can be seen with reference to FIG. 2, the conductor 204is disposed coaxially around the TSV 202. The conductor 204 of thisparticular embodiment has three turns (204 a, 204 b, and 204 c) aboutthe TSV 202. As described above, rather than having a single pitchangle, the conductor 204 has a stepped structure, whereby turns with apitch angle of 0 (e.g., turns laying in a plane of the device 200) areconnected by vertical connecting portions that are staggeredcircumferentially around the turns. In this regard, planar turns 204 aand 204 b are connected by a vertical connecting portion 206, and planarturns 204 b and 204 c are connected by a vertical connecting portion208. This stepped structure facilitates fabrication of the conductor 204using simple semiconductor processing techniques (e.g., planarmetallization steps for the turns and via formation for the verticalconnecting portions). Moreover, as shown in FIG. 2, the turns 204 a, 204b, and 204 c of the conductor 204 trace a rectangular shape around theTSV 202 when oriented in a planar view.

In accordance with one embodiment, the TSV 202 can optionally (e.g., asshown with dotted lines) include a core material 202 a surrounded by oneor more coaxial layers, such as layers 202 b and 202 c. For example, thecore 202 a and the outer coaxial layer 202 c can include magneticmaterials, while the middle coaxial layer 202 b can include anon-magnetic material, to provide a laminate structure that can reduceeddy current losses. Although the TSV 202 is illustrated in FIG. 2 asoptionally including a three-layer structure (e.g., a core 202 asurrounded by two coaxially laminated layers 202 b and 202 c), in otherembodiments any number of coaxial laminate layers can be used tofabricate a TSV.

Although in the foregoing embodiments shown in FIG. 1 and FIG. 2substantially helical conductors have been illustrated as having threeturns about a TSV, the number of turns of a substantially helicalconductor around a TSV can vary in accordance with different embodimentsof the technology. As is shown in the example embodiment of FIG. 2, asubstantially helical conductor need not make an integer number of turnsabout a TSV (e.g., the top and/or bottom turn may not be a completeturn). Providing more turns can increase the inductance of an inductorcompared to having fewer turns, but at an increase in the cost andcomplexity of fabrication (e.g., more fabrication steps). The number ofturns can be as low as one, or as high as is desired. When coupledinductors are provided with the same number of windings, they can coupletwo electrically isolated circuits without stepping up or down thevoltage from the primary winding.

For example, FIG. 3 is a simplified cross-sectional view of a multi-diesemiconductor device 300 including coupled inductors with TSV coresconfigured in accordance with an embodiment of the present technology.The device 300 includes a first die 301 and a second die 351. The firstdie has a first substrate 301 a and a first insulating material 301 b.The device 300 further includes a first TSV 302 that extends at leastsubstantially through the first die 301 (e.g., extending fromapproximately the bottom of the first substrate 301 a to beyond an uppersurface of the first substrate 301 a—completely through the firstsubstrate 301 a—and into the first insulating material 301 b). Thedevice 300 also includes a first substantially helical conductor 303(“conductor 303”) disposed around the first TSV 302. In the presentembodiment, the first conductor 303 is shown to include four completeturns (303 a, 303 b, 303 c and 303 d) around the first TSV 302. Thefirst conductor 303 can be operably connected to other circuit elements(not shown) by leads 320 a and 320 b.

The second die 351 has a second substrate 351 a, a second insulatingmaterial 351 b, and a second TSV 352 in the second die 351 extending outof the second substrate 351 a and into the second insulating material351 b. The device 300 further includes a second substantially helicalconductor 353 (“conductor 353”) disposed around the second TSV 352. Inthe present embodiment, the second conductor 353 is shown to includethree complete turns (353 a, 353 b, and 353 c) around the second TSV352. The second conductor 353 can be operably connected to other circuitelements (not shown) by leads 370 a and 370 b.

As set forth above, coaxial columns of TSVs can be coupled in any one ofa number of ways to improve the magnetic permeability thereof. Forexample, in the present embodiment of FIG. 3, the first and second TSVs302 and 352 are mechanically coupled by a direct connection. Unlike TSVsconfigured to carry electrical signals, the electrical resistance of theconnection between these two TSVs 302 and 352 is not a primary concernin configuring a path with high magnetic permeability. Accordingly, manyof the steps utilized to improve the electrical connection betweencoupled TSVs (e.g., under bump metallization, solder ball formation,solder reflow, etc.) can be omitted from a manufacturing method of thedevice 300, in accordance with one embodiment of the present technology.

According to one embodiment, the first conductor 303 is configured toinduce a magnetic field in the first and second TSVs 302 and 352 inresponse to a current passing through the first conductor 303 (e.g.,provided by a voltage applied across leads 320 a and 320 b). By changingthe current passing through the first conductor 303 (e.g., by applyingan alternating current, or by repeatedly switching between high and lowvoltage states), a changing magnetic field can be induced in the twoTSVs 302 and 352, which in turn induces a changing current in the secondconductor 353. In this fashion, signals and/or power can be coupledbetween a circuit comprising the first conductor 303 and anothercomprising the second conductor 353 (e.g., operating the device 300 as apower transformer).

The first conductor 303 and the second conductor 353 shown in FIG. 3have different numbers of turns. As will be readily understood by oneskilled in the art, this arrangement allows the device 300 to beoperated as a step-up or step-down transformer (depending upon whichsubstantially helical conductor is utilized as the primary winding andwhich the secondary winding). For example, the application of a firstchanging current (e.g., 4V of alternating current) to the firstconductor 303 will induce a changing current with a lower voltage (e.g.,3V of alternating current) in the second conductor 353, given the 4:3ratio of turns between the primary and secondary windings in thisconfiguration. When operated as a step-up transformer (e.g., byutilizing the second conductor 353 as the primary winding, and the firstconductor 303 as the secondary winding), the application of a firstchanging current (e.g., 3V of alternating current) to the secondconductor 353 will induce a changing current with a higher voltage(e.g., 4V of alternating current) in the first conductor 303, given the3:4 ratio of turns between the primary and secondary windings in thisconfiguration.

Although the foregoing embodiments of FIGS. 1 and 3 have illustratedsemiconductor devices with two dies, in other embodiments of the presenttechnology, semiconductor devices can include larger stacks of anynumber of dies with coupled inductors. For example, FIG. 4 is asimplified cross-sectional view of a multi-die semiconductor deviceincluding coupled inductors with TSV cores configured in accordance withan embodiment of the present technology. The device 400 includes a firstdie 410, a second die 420 and a third die 430. The first die has a firstsubstrate 411 a and a first insulating material 411 b. The device 400further includes a first TSV 412 that extends at least substantiallythrough the first die 410 (e.g., extending from approximately the bottomof the first substrate 411 a to beyond an upper surface of the firstsubstrate 411 a—completely through the first substrate 411 a—and intothe first insulating material 411 b). The device 400 also includes afirst substantially helical conductor 413 (“conductor 413”) disposedaround the first TSV 412. In the present embodiment, the first conductor413 is shown to include three complete turns around the first TSV 412.The first conductor 413 can be operably connected to other circuitelements (not shown) by leads 414 a and 414 b.

The second die 420 includes a second substrate 421 a, a secondinsulating material 421 b, and a second TSV 422 that extends at leastsubstantially through the second die 420 (e.g., extending fromapproximately the bottom of the substrate 421 a to beyond an uppersurface of the substrate 421 a—completely through the second substrate421 a—and into the second insulating material 421 b). The device 400also includes a second substantially helical conductor 423 (“conductor423”) disposed around the second TSV 422. In the present embodiment, thesecond conductor 423 is shown to include three complete turns around thesecond TSV 422. The second conductor 423 can be operably connected byleads 424 a and 424 b to other circuit elements (not shown), includingone or more rectifiers to revert a coupled alternating current to DC andone or more capacitors or other filter elements to provide steadycurrent.

The third die 430 includes a third substrate 431 a, a third insulatingmaterial 431 b, and a third TSV 432 in the third die 430 extending outof the third substrate 431 a and into the third insulating material 431b. The device 400 also includes a third substantially helical conductor433 (“conductor 433”) disposed around the third TSV 432. In the presentembodiment, the third conductor 433 is shown to include three completeturns around the third TSV 432. The third conductor 433 can be operablyconnected to other circuit elements (not shown), by leads 434 a and 434b which connect the third conductor 433 to pads 436 a and 436 b.

According to one embodiment, the third conductor 433 is configured toinduce a magnetic field in the three TSVs 412, 422 and 432 in responseto a current passing through the third conductor 433 (e.g., provided bya voltage applied across the pads 436 a and 436 b). By changing thecurrent passing through the third conductor 433 (e.g., by applying analternating current, or by repeatedly switching between high and lowvoltage states), a changing magnetic field can be induced in the threeTSVs 412, 422 and 432, which in turn induces a changing current in thefirst and second conductors 413 and 423 (e.g., through which the firstand second TSVs pass). In this fashion, signals and/or power can becoupled between a circuit comprising the third conductor 433 and otherscomprising the first and second conductors 413 and 423.

As previously set forth, coaxial columns of TSVs can be coupled in anyone of a number of ways to improve the magnetic permeability thereof.For example, in the present embodiment of FIG. 4, the first and secondTSVs 412 and 422 are magnetically coupled across a small gap 415 (e.g.,filled by insulating material and/or substrate material). The second andthird TSVs 422 and 432 are similarly magnetically coupled across anothersmall gap 425. Unlike TSVs configured to carry electrical signals, aninsulating gap between coaxial TSVs is not a significant impediment inproviding a path with high magnetic permeability. Accordingly, a coaxialcolumn of coupled TSVs can be solely magnetically coupled, rather thanmechanically or electrically coupled, in accordance with one embodimentof the present technology.

Although the foregoing embodiments of FIGS. 1 through 4 have illustratedinductors with a single substantially helical conductor disposed aroundeach TSV, other embodiments of the present technology can be configuredwith more than one such conductor around a TSV, as set forth in greaterdetail below. For example, FIG. 5 is a simplified cross-sectional viewof a multi-die semiconductor device 500 including coupled inductors withTSV cores configured in accordance with an embodiment of the presenttechnology. The device 500 includes a first die 510 and a second die520. The first die includes a first substrate 511 a and a firstinsulating material 511 b. The device 500 further includes a first TSV512 that extends at least substantially through the first die 510 (e.g.,extending from approximately the bottom of the first substrate 511 a tobeyond an upper surface of the first substrate 511 a—completely throughthe first substrate 511 a—and into the first insulating material 511 b).The device 500 also includes a first substantially helical conductor 513(“conductor 513”) disposed around the first TSV 512. In the presentembodiment, the first conductor 513 is shown to include three completeturns around the first TSV 512. The first conductor 513 can be operablyconnected to other circuit elements (not shown) by leads 514 a and 514b.

The second die 520 includes second substrate 521 a, a second insulatingmaterial 521 b, and a second TSV 522 that extends out of the secondsubstrate 521 a and into the second insulating material 521 b. Thesecond TSV 522 is magnetically coupled to the first TSV 512 in the firstdie 510 across a small gap 515. The device 500 also includes a secondsubstantially helical conductor 523 a (“conductor 523 a”) disposedaround a portion of the second TSV 522, and a third substantiallyhelical conductor 523 b (“conductor 523 b”) disposed around anotherportion of the second TSV 522. In the present embodiment, the second andthird conductors 523 a and 523 b are shown to each include threecomplete turns around the second TSV 522. The second conductor 523 a canbe operably connected to other circuit elements (not shown) by leads 524a and 524 b, and the third conductor 523 b can be operably connected tostill other circuit elements (not shown) by leads 524 c and 524 d.

According to one embodiment, the first conductor 513 is configured toinduce a magnetic field in the two TSVs 512 and 522 in response to acurrent passing through the first conductor 513 (e.g., provided by avoltage applied across the leads 514 a and 514 b). By changing thecurrent passing through the first conductor 513 (e.g., by applying analternating current, or by repeatedly switching between high and lowvoltage states), a changing magnetic field can be induced in the twoTSVs 512 and 522, which in turn induces a changing current in the secondand third conductors 523 a and 523 b. In this fashion, signals and/orpower can be coupled between a circuit comprising the first conductor513 and others comprising the second and third conductors 523 a and 523b.

Although FIG. 5 illustrates an embodiment having a die with twosubstantially helical conductors or windings disposed around a TSV attwo different heights (e.g., coaxially but not concentrically), in otherembodiments, multiple substantially helical conductors with differentdiameters can be provided at the same height (e.g., with radially-spacedconductive turns in the same layers). As the inductance of asubstantially helical conductor depends, at least in part, on itsdiameter and radial spacing from the TSV around which it is disposed,such an approach can be used where a reduction in the number of layerprocessing steps is more desirable than an increase in the inductance ofthe substantially helical conductor so radially spaced.

The foregoing example embodiments illustrated in FIGS. 1 through 5include inductors having an open core (e.g., a core wherein the magneticfield passes through a higher magnetic permeability material for onlypart of the path of the magnetic field), but embodiments of the presenttechnology can also be provided with a closed core. For example, FIG. 6is a simplified cross-sectional view of a multi-die semiconductor device600 including coupled inductors with TSV cores configured in accordancewith an embodiment of the present technology. Referring to FIG. 6, thedevice 600 includes a first die 610 and a second die 620. The first die610 includes a first substrate 611 a and a first insulating material 611b. The device 600 further includes first and second TSVs 612 a and 612 bthat extend at least substantially through the first die 610 (e.g.,extending from approximately the bottom of the first substrate 611 a tobeyond an upper surface of the first substrate 611 a—completely throughthe first substrate 611 a—and into the first insulating material 611 b).The device 600 further includes a first substantially helical conductor613 (“conductor 613”) disposed around the first TSV 612 a. In thepresent embodiment, the first conductor 613 is shown to include threecomplete turns around the first TSV 612 a. The first and second TSVs 612a and 612 b are coupled above the first conductor 613 by an uppercoupling member 617 in the first die 610. The first conductor 613 can beoperably connected to other circuit elements (not shown) by leads 614 aand 614 b.

The second die 620 includes a second substrate 621 a, a secondinsulating material 621 b, and third and fourth TSVs 622 a and 622 bthat extend out of the second substrate 621 a and into the secondinsulating material 621 b. The third TSV 622 a is coupled to the firstTSV 612 a in the first die 610 by a first solder connection 615 a, andthe fourth TSV 622 b is coupled to the second TSV 612 b in the first die610 by a second solder connection 615 b. The device further includes asecond substantially helical conductor 623 (“conductor 623”) disposedaround the third TSV 622 a. In the present embodiment, the secondconductor 623 is shown to include three complete turns around the thirdTSV 622 a. The third and fourth TSVs 622 a and 622 b are coupled belowthe second conductor 623 by a lower coupling member 627 in the seconddie 620. The second conductor 623 can be operably connected to othercircuit elements (not shown) by leads 624 a and 624 b.

The upper coupling member 617 and the lower coupling member 627 caninclude a magnetic material, having a magnetic permeability higher thanthat of the first and second substrates 611 a and 621 a and/or the firstand second insulating materials 611 b and 621 b. The magnetic materialof the upper and lower coupling members 617 and 627 can be either thesame material as that of the four TSVs 612 a, 612 b, 622 a and 622 b, ora different material. The magnetic material of the upper and lowercoupling members 617 and 627 can be a bulk material (e.g., nickel, iron,cobalt, niobium, or an alloy thereof), or a laminated material withdiffering layers (e.g., of magnetic material and non-magnetic material).Laminated layers of magnetic and non-magnetic material can help toreduce eddy current losses in the upper and lower coupling members 617and 627. In accordance with one aspect of the present technology, thefour TSVs 612 a, 612 b, 622 a and 622 b, together with the uppercoupling member 617 and the lower coupling member 627, can provide aclosed path for the magnetic field induced by the second conductor 623,such that the inductance of the device 600 is greater than it would beif only the four TSVs 612 a, 612 b, 622 a and 622 b were provided.

According to one embodiment, the second conductor 623 is configured toinduce a magnetic field in the four TSVs 612 a, 612 b, 622 a and 622 b(and in the upper and lower coupling members 617 and 627) in response toa current passing through the second conductor 623 (e.g., provided by avoltage applied across the leads 624 a and 624 b). By changing thecurrent passing through the second conductor 623 (e.g., by applying analternating current, or by repeatedly switching between high and lowvoltage states), a changing magnetic field can be induced in the fourTSVs 612 a, 612 b, 622 a and 622 b (and in the upper and lower couplingmembers 617 and 627), which in turn induces a changing current in thefirst conductor 613. In this fashion, signals and/or power can becoupled between a circuit comprising the second conductor 623 andanother comprising the first conductor 613.

Although in the example embodiment illustrated in FIG. 6 coupledinductors are illustrated sharing a closed core (e.g., a core in which asubstantially continuous path of high magnetic permeability materialpasses through the middle of a conductive winding), in otherembodiments, one or both of the upper and lower coupling members 617 and627 could be omitted. In such an embodiment, a secondary coaxial columnof TSVs (e.g., in addition to the coaxial column of TSVs around whichthe windings are disposed) with elevated magnetic permeability could besituated near the coaxial column of TSVs around which the windings aredisposed to provide an open core embodiment with improved inductanceover an embodiment in which the secondary coaxial column of TSVs was notpresent.

According to one embodiment, a closed magnetic core as illustrated byway of example in FIG. 6 can provide additional space in which one ormore windings can be disposed (e.g., to provide a transformer or powercouple). For example, although FIG. 6 illustrates a device in which twowindings are disposed on the same coaxial column of TSVs, with aproximate column of TSVs having no windings, in another embodiment, twoproximate columns of coaxial TSVs could be provided with a singlewinding on each column (e.g., a primary winding on the first column in afirst die, and a secondary winding on the second column in a seconddie). Alternatively, additional windings can be provided in the spaceprovided by a closed magnetic core or a proximate TSV in an open-coreembodiment, to provide more than two coupled inductors that all interactwith the same magnetic field. For example, FIG. 7 is a simplifiedcross-sectional view of coupled inductors with through-substrate viacores configured in accordance with an embodiment of the presenttechnology. As can be seen with reference to FIG. 7, a device 700includes a first die 710 and a second die 720. The first die 710includes a first substrate 711 a and a first insulating material 711 b.The device 700 further includes first and second TSVs 712 a and 712 bthat extend at least substantially through the first die 710 (e.g.,extending from approximately the bottom of the first substrate 711 a tobeyond an upper surface of the first substrate 711 a—completely throughthe first substrate 711 a—and into the first insulating material 711 b).The device 700 further includes a first substantially helical conductor713 a (“conductor 713 a”) disposed around the first TSV 712 a. In thepresent embodiment, the first conductor 713 a is shown to include threecomplete turns around the first TSV 712 a. The device 700 furtherincludes a second substantially helical conductor 713 b (“conductor 713b”) disposed around the second TSV 712 b. In the present embodiment, thesecond conductor 713 b is shown to include three complete turns aroundthe second TSV 712 b. The first and second TSVs 712 a and 712 b arecoupled above the first and second conductors 713 a and 713 b by anupper coupling member 717 in the first die 710. The first conductor 713a can be operably connected to other circuit elements (not shown) byleads 714 a and 714 b, and the second conductor 713 b can be operablyconnected to other circuit elements (not shown) by leads 714 c and 714d.

The second die 720 includes a second substrate 721 a, a secondinsulating material 721 b, and third and fourth TSVs 722 a and 722 bthat extend out of the second substrate 721 a and into the secondinsulating material 721 b. The third TSV 722 a is coupled to the firstTSV 712 a in the first die 710 by a first solder connection 715 a, andthe fourth TSV 722 b is coupled to the second TSV 712 b in the first die710 by a second solder connection 715 b. In other embodiments, TSVs inadjacent dies can be coupled using any one of a number of otherinterconnect methods (e.g., copper-to-copper bonding, pill and pad,interference fit, mechanical, etc.). The device further includes a thirdsubstantially helical conductor 723 (“conductor 723”) disposed aroundthe third TSV 722 a. In the present embodiment, the third conductor 723is shown to include three complete turns around the third TSV 722 a. Thethird and fourth TSVs 722 a and 722 b are coupled below the thirdconductor 723 by a lower coupling member 727 in the second die 720. Thethird conductor 723 can be operably connected to other circuit elements(not shown) by leads 724 a and 724 b.

The upper coupling member 717 and the lower coupling member 727 caninclude a magnetic material having a magnetic permeability higher thanthat of the first and second substrates 711 a and 721 a and/or the firstand second insulating materials 711 b and 721 b. The magnetic materialof the upper and lower coupling members 717 and 727 can be either thesame material as that of the four TSVs 712 a, 712 b, 722 a and 722 b, ora different material. The magnetic material of the upper and lowercoupling members 717 and 727 can be a bulk material (e.g., nickel, iron,cobalt, niobium, or an alloy thereof), or a laminated material withdiffering layers (e.g., of magnetic material and non-magnetic material).Laminated layers of magnetic and non-magnetic material can help toreduce eddy current losses in the upper and lower coupling members 717and 727. In accordance with one aspect of the present technology, thefour TSVs 712 a, 712 b, 722 a and 722 b, together with the uppercoupling member 717 and the lower coupling member 727, can provide aclosed path for the magnetic field induced by the third conductor 723,such that the inductance of the device 700 is greater than it would beif only the four TSVs 712 a, 712 b, 722 a and 722 b were provided.

According to one embodiment, the third conductor 723 is configured toinduce a magnetic field in the four TSVs 712 a, 712 b, 722 a and 722 b(and in the upper and lower coupling members 717 and 727) in response toa current passing through the third conductor 723 (e.g., provided by avoltage applied across the leads 724 a and 724 b). By changing thecurrent passing through the third conductor 723 (e.g., by applying analternating current, or by repeatedly switching between high and lowvoltage states), a changing magnetic field can be induced in the fourTSVs 712 a, 712 b, 722 a and 722 b (and in the upper and lower couplingmembers 717 and 727), which in turn induces a changing current in thefirst and second conductors 713 a and 713 b. In this fashion, signalsand/or power can be coupled between a circuit comprising the thirdconductor 723 and others comprising the first and second conductors 713a and 713 b.

Although in the embodiment illustrated in FIG. 7 two coupled inductorson proximate are shown with the same number of turns, in otherembodiments of the present technology different numbers of windings canbe provided on similarly-configured inductors. As will be readilyunderstood by one skilled in the art, by providing coupled inductorswith different numbers of windings, a device so configured can beoperated as a step-up or step-down transformer (depending upon whichconductor is utilized as the primary winding and which the secondarywinding).

Although in the embodiments illustrated in FIGS. 6 and 7 a singleadditional coaxial column of coupled TSVs is provided to enhance themagnetic permeability of the return path for the magnetic fieldgenerated by a primary winding around a first coaxial column of TSVs, inother embodiments of the present technology multiple return path coaxialcolumns of TSVs can be provided to further improve the inductance of theinductors so configured. For example, embodiments of the presenttechnology may use two, three, four, or any number of additional coaxialcolumns of coupled TSVs to provide a return path for the magnetic fieldwith enhanced magnetic permeability. Such additional coaxial columns ofcoupled TSVs may be coupled by upper and/or lower coupling members tothe coaxial column of coupled TSVs around which one or moresubstantially helical conductors are disposed (e.g., a closed coreconfiguration), or may merely be sufficiently proximate to concentratesome of the magnetic flux of the return path of the magnetic field toenhance the performance of the device so configured.

Although in the foregoing examples set forth in FIGS. 1 to 7 eachsubstantially helical conductor has been illustrated as having a singleturn about a TSV at a given distance from the surface of a correspondingsubstrate, in other embodiments a substantially helical conductor canhave more than one turn about a TSV at the same distance from thesubstrate surface (e.g., multiple turns arrange coaxially at eachlevel). For example, FIG. 8 is a simplified perspective view of astructure 800 comprising a substantially helical conductor 804(“conductor 804”) disposed around a through-substrate via 802 configuredin accordance with an embodiment of the present technology. As can beseen with reference to FIG. 8, the conductor 804 includes a firstsubstantially helical conductor 804 a (“conductor 804 a”) disposedaround the TSV 802, which is connected to a second coaxially-alignedsubstantially helical conductor 804 b (“conductor 804 b”), such that asingle conductive path winds downward around TSV 802 at a first averageradial distance, and winds back upward around TSV 802 at a secondaverage radial distance. Accordingly, the conductor 804 includes twoturns about the TSV 802 (e.g., the topmost turn of conductor 804 a andthe topmost turn of conductor 804 b) at the same position along thelongitudinal dimension “L” of the TSV 802. In another embodiment, asubstantially helical conductor could make two turns about a TSV at afirst level (e.g., spiraling outward), two turns about a TSV at a secondlevel (e.g., spiraling inward), and so on in a similar fashion for asmany turns as were desired.

FIGS. 9A-9F are simplified views of a device 900 having an inductor witha through-substrate via core in various states of a manufacturingprocess in accordance with an embodiment of the present technology. InFIG. 9A, a substrate 901 is provided in anticipation of furtherprocessing steps. The substrate 901 may be any one of a number ofsubstrate materials, including silicon, glass, gallium arsenide, galliumnitride, organic laminates, molding compounds (e.g., for reconstitutedwafers for fan-out wafer-level processing) and the like. In FIG. 9B, afirst turn 903 of a substantially helical conductor has been disposed ina layer of the insulating material 902 over the substrate 901. Theinsulating material 902 can be any one of a number of insulatingmaterials which are suitable for semiconductor processing, includingsilicon oxide, silicon nitride, polyimide, or the like. The first turn903 can be any one of a number of conducting materials which aresuitable for semiconductor processing, including copper, gold, tungsten,alloys thereof, or the like.

In FIG. 9C, a second turn 904 of the substantially helical conductor hasbeen disposed in the now thicker layer of the insulating material 902,and spaced from the first turn 903 by a layer of the insulating material902. The second turn 904 is electrically connected to the first turn 903by a first via 905. A second via 906 has also been provided to route anend of the first turn 903 to an eventual higher layer of the device 900.In FIG. 9D, a third turn 907 of the substantially helical conductor hasbeen disposed in the now thicker layer of the insulating material 902,and spaced from the second turn 904 by a layer of the insulatingmaterial 902. The third turn 907 is electrically connected to the secondturn 904 by a third via 908. The second via 906 has been furtherextended to continue routing an end of the first turn 903 to an eventualhigher layer of the device 900.

Turning to FIG. 9E, the device 900 is illustrated in a simplifiedperspective view after an opening 909 has been etched through theinsulating material 902 and into the substrate 901. The opening 909 isetched substantially coaxially with the turns 903, 904 and 907 of thesubstantially helical conductor using any one of a number of etchingoperations capable of providing a substantially vertical opening with ahigh aspect ratio. For example, deep reactive ion etching, laserdrilling, or the like can be used to form the opening 909. In FIG. 9F, aTSV 910 has been disposed in the opening 909. The TSV 910 can include amagnetic material (e.g., a material with a higher magnetic permeabilitythan the substrate 901 and/or the insulating material 902) to increasethe magnetic field in the TSV 910 when current is flowing through thesubstantially helical conductor. The magnetic material can beferromagnetic, ferrimagnetic, or a combination thereof. The TSV 910 caninclude more than one material, either in a bulk material of a singlecomposition, or in discrete regions of different materials (e.g.,coaxial laminate layers). For example, the TSV 910 can include nickel,iron, cobalt, niobium, or alloys thereof. Laminated layers of magneticand non-magnetic material can help to reduce eddy current losses in theTSV 910. The TSV 910 can be provided in a single metallization stepfilling in the opening 909, or in multiple steps of laminating layers(e.g., multiple magnetic layers separated by non-magnetic layers). Inone embodiment, to provide a TSV with a multiple layer structure, amixture of conformal and bottom-up fill plating operations can beutilized (e.g., a conformal plating step to partially fill and narrowthe etched opening with a first material, and a subsequent bottom-upplating step to completely fill the narrowed opening with a secondmaterial).

Turning to FIG. 9G, the device 900 is illustrated after the substrate901 has been thinned to expose or reduce the distance between a bottomsurface of the substrate 901 and a bottom end of the TSV 910, to providea thinned die 911. In FIG. 9H, the device 900 is illustrated after thethinned die 911 has been disposed over a second die 912 in which anotherTSV is surrounded by a substantially helical conductor. The TSV 910 andthe coaxially aligned TSV of the second die 912 can be coupled in avariety of ways, including by solder connection, copper-to-copperbonding, pill and pad, interference fit, mechanical connection, ormagnetic coupling across a small gap (e.g., of insulating materialand/or substrate material).

FIG. 10 is a flow chart illustrating a method of manufacturing aninductor with a through-substrate via core in accordance with anembodiment of the present technology. The method begins in step 1010, inwhich a substrate is provided. In step 1020, a substantially helicalconductor is disposed in an insulating material over the substrate. Instep 1030, an opening is etched through the insulating material and intothe substrate along an axis of the substantially helical conductor. Instep 1040, a TSV is disposed into the opening. In step 1050, thesubstrate is thinned to expose or reduce the distance between a bottomsurface of the substrate and a bottom end of the TSV. In step 1060, thedie comprising the first substrate is disposed over a second die with acoaxially aligned TSV around which is disposed another substantiallyhelical conductor. In step 1070, the first TSV and the second TSV arecoupled (e.g., by a solder connection, or a mechanical connection, or bya magnetic coupling across a gap).

From the foregoing, it will be appreciated that specific embodiments ofthe invention have been described herein for purposes of illustration,but that various modifications may be made without deviating from thescope of the invention. Accordingly, the invention is not limited exceptas by the appended claims.

I claim:
 1. A semiconductor device, comprising: a first die including: afirst through-substrate via (TSV) extending at least substantiallythrough the first die, and a first substantially helical conductordisposed around the first TSV; and a second die including: a second TSVcoupled to the first TSV, and a second substantially helical conductordisposed around the second TSV, wherein the second TSV is coupled to thefirst TSV by a solder connection, and wherein the solder connection isseparated from the first and second TSVs by a barrier materialconfigured to prevent solder diffusion into the first and second TSVs.2. The semiconductor device of claim 1, wherein the first substantiallyhelical conductor is configured to induce a change in a magnetic fieldin the first and second TSVs in response to a first changing current inthe first substantially helical conductor, and wherein the secondsubstantially helical conductor is configured to have a second changingcurrent induced therein in response to the change in the magnetic fieldin the second TSV.
 3. The semiconductor device of claim 1, wherein thesolder connection comprises a magnetic material.
 4. The semiconductordevice of claim 1, wherein the first TSV and the second TSV arecoaxially aligned.
 5. The semiconductor device of claim 1, wherein thefirst and second TSVs comprise a ferromagnetic or a ferrimagneticmaterial.
 6. The semiconductor device of claim 1, wherein the first TSVis separated from the first substantially helical conductor by aninsulating material, and the second TSV is separated from the secondsubstantially helical conductor by an insulating material.
 7. Thesemiconductor device of claim 1, wherein the first substantially helicalconductor comprises more than one turn around the first TSV, and thesecond substantially helical conductor comprises more than one turnaround the second TSV.
 8. The semiconductor device of claim 1, whereinthe first substantially helical conductor is coaxially aligned with thefirst TSV.
 9. The semiconductor device of claim 1, wherein the secondsubstantially helical conductor is coaxially aligned with the secondTSV.
 10. A semiconductor device, comprising: a first die including: afirst through-substrate via (TSV) extending at least substantiallythrough the first die, a second TSV extending at least substantiallythrough the first die, and a first substantially helical conductordisposed around one of the first and second TSVs, a second dieincluding: a third TSV coupled to the first TSV, a fourth TSV coupled tothe second TSV, and a second substantially helical conductor disposedaround one of the third and fourth TSVs, wherein the third TSV iscoupled to the first TSV by a first solder connection, wherein thefourth TSV is coupled to the second TSV by a second solder connection,and wherein the first solder connection is separated from the first andthird TSVs by a barrier material configured to prevent solder diffusioninto the first and third TSVs.
 11. The semiconductor device of claim 10,wherein the first substantially helical conductor is configured toinduce a change in a magnetic field in the first, second, third andfourth TSVs in response to a first changing current in the firstsubstantially helical conductor, and wherein the second substantiallyhelical conductor is configured to have a second changing currentinduced therein in response to the change in the magnetic field in theTSV around which the second substantially helical conductor is disposed.12. The semiconductor device of claim 10, wherein the first, second,third and fourth TSVs comprise a ferromagnetic or a ferrimagneticmaterial.
 13. The semiconductor device of claim 10, wherein the secondTSV is coupled to the first TSV by an upper coupling member above thefirst substantially helical conductor.
 14. The semiconductor device ofclaim 13, wherein the upper coupling member comprises a ferromagnetic ora ferrimagnetic material.
 15. The semiconductor device of claim 10,wherein the fourth TSV is coupled to the third TSV by a lower couplingmember below the second substantially helical conductor.
 16. Thesemiconductor device of claim 15, wherein the lower coupling membercomprises a ferromagnetic or a ferrimagnetic material.
 17. Thesemiconductor device of claim 10, wherein the third and fourth TSVsextend at least substantially through the second die.
 18. Thesemiconductor device of claim 10, wherein the second solder connectionis separated from the second and fourth TSVs by a barrier materialconfigured to prevent solder diffusion into the second and fourth TSVs.19. The semiconductor device of claim 10, wherein the first and secondsolder connections comprise a magnetic material.
 20. The semiconductordevice of claim 10, wherein the first substantially helical conductor isdisposed around the first TSV, and the second substantially helicalconductor is disposed around the third TSV.